With the continuous advancement of advanced packaging, the proportion of packaging and testing equipment in the semiconductor equipment industry has gradually increased. Die bonding is an important link in the post-process of semiconductor manufacturing. This article will introduce you in detail about die bonding techniques in semiconductor and die bonder machine.
What is bonding?
In semiconductor technology, “bonding” refers to fixing the wafer chip on the substrate. The bonding process can be divided into two types: traditional method and advanced method.
The traditional method uses die bonding (or die attach) and wire bonding, while the advanced method uses flip-chip bonding technology developed by IBM in the late 1960s. The flip-chip bonding technology combines chip bonding and wire bonding, and connects the chip and the packaging substrate by forming a bump on the chip pad.
What are die bonding techniques in semiconductor?
Die bonding process is an important process for semiconductor chip manufacturing. It is the process of separating the chip from the carrier, and also the process of connecting the chip to the packaging substrate. In semiconductor chip manufacturing, the quality and efficiency of the die bonding process has an important impact on the performance and cost of the chip.
Die bonding process
The die bonding process is a very important process in semiconductor chip manufacturing. The quality and efficiency of the die bonding process have an important impact on the performance and cost of the chip. In order to ensure the quality and efficiency of the die bonding process, it is necessary to use high-precision die bonder machine and process control technology.
The main steps of the die bonding process include: chip positioning, glue coating, chip alignment, heat curing, carrier separation and cleaning, etc.
- The chips need to be positioned on the carrier, which requires the use of sophisticated positioning equipment.
- Apply glue between the chip and the carrier to ensure the bond between them.
- Chips need to be aligned to the package substrate which requires the use of high precision alignment equipment.
- Heat cures the glue to ensure a strong bond between the chip and package substrate.
- Separating the carrier from the chip and cleaning the chip and package substrate to ensure their surfaces are clean.
What is the difference between die bonding and wire bonding?
Wire bonding is a method of connecting metal leads to pads, that is, a technology that connects internal and external chips. From a structural point of view, the metal leads act as a bridge between the pads of the chip (primary bonding) and the carrier pads (secondary bonding). In the early days, lead frame was used as the carrier substrate, but with the rapid development of technology, more and more PCBs are now used as the substrate.
The wire bonding that connects two independent pads is very different in the material of the wire, bonding conditions, and bonding position (in addition to connecting the chip and the substrate, but also connecting two chips or two substrates).
Die boning refers to fixing the chip on the PCB ( it can be FR4 hard board, FPC or ceramic substrate). The equipment that completes this process is called a die bonder machine, and a complete bonding process is: feeding → dispensing → chip removal → bonding. There are currently four bonding methods: silver paste bonding, eutectic bonding, flip chip bonding, and thermosonic flip chip bonding.
What is die bonder machine?
Die bonder, also called SMT mounter, the most critical and core device in the die attach link of chip packaging and testing. Grab the chip from the cut wafer, place it on the die flag corresponding to the substrate, and use epoxy to bond the chip and the substrate. The placement machine can place components at high speed and high precision, and realize key steps such as positioning, alignment, flip chip, and continuous placement.
What are the types of die bonder machine?
Die bonder machine is divided into FC package placement machine, FO package placement machine and 2.5D/3D placement machine.
According to the application type : it can be divided into IC die bonder, discrete device die bonder, LED die bonder (SMT die bonder and COB die bonder), mainly used in semiconductor electric chips, optical chips, optical modules, silicon photonics devices, sensors and other packaging processes.
Die bonding is applied to the key process of subsequent packaging and testing. The higher the requirements for accuracy and speed, the faster the UPH and the more prone to deviations. The quality of die bonding will directly affect the follow-up wiring and other links, and directly affect the production capacity, chip packaging and testing yield and cost :
1. Die bonder can be divided into ultra-high precision equipment, medium and high precision equipment, and low precision equipment;
2. Ultra-high-precision die bonder, the accuracy can be within ±3~5μm, representing the brand Datacon, MRSI, ASM equipment. In the field of IC advanced packaging, currently the world’s highest ASMPT COS placement machine with a precision of ±1μm. Huafeng AvantGo 2060W placement machine with the highest precision of ±3μm in the industry;
3. Medium and high-precision die bonding machine, the precision is in the range of ±25μm, and the UPH is about 15~20K. The main brands are ASM, ESEC, Yamaha, Hitachi, etc.
4. The general accuracy of IC die bonders produced in China is above ±25μm, and the UPH is between 12-15K.
What are the main application of die bonder machine?
Die bonder is mainly used in the packaging process of semiconductor electronic chips, optical chips, optical modules, silicon optical devices, sensors, etc. Here we mainly introduce the applications in the semiconductor industry and the electronics industry, taking China as an example.
1. Semiconductor industry:
The die bonder machines used in the semiconductor industry, China has the highest localization ratio of LED die bond machines, reaching over 90%; the localization ratio of IC die bonder and discrete device die bonder is relatively low, both less than 10%. With the gradual concentration of global semiconductor projects in China.
2. Electronic industry:
Die bonder used in electronics industry among them, the localization ratio of all types of bonding machines in China is not high, the localization ratio of COG bonding machines is about 20%, and the localization ratio of COB bonding machines and COF bonding machines is about 5%.
Global main die bonder manufacturers and suppliers
The core technology of die bonder has always been mastered by a small number of large companies, and the technical property rights are protected in the form of patents, which has led to the monopoly of Japan, the United States and Europe in the high-precision die bonder machine market. At present, the global market size of die bond exceeds 2 billion US dollars, and ASMPT and BESI are monopolized.
ASMPT is the world’s largest supplier of semiconductor component integration and packaging equipment. The company was formerly known as ASM Pacific Technology, and officially changed its name to ASMPT Limited on August 1, 2022, and announced that the global business will be unified under the ASMPT brand. Headquartered in Singapore, ASMPT covers the semiconductor solutions and SMT solutions segments.
ASMPT placement machine is one of the mainstream placement machine brands in the world. The global market share is about 30%, and the Chinese market share is about 70%. It is also one of the manufacturers that can provide new Mini LED die-bonding technology in the market.
ASMPT has the world’s highest precision placement machine and flip chip placement machine.
1. With ±1.0 µm accuracy, Nova Plus is suitable for semiconductor advanced packaging (TSV, eWLB, fan-out, WLP, 3D, Stack Die), MEMS, automotive sensors, RFID and optoelectronic systems;
2. AFC Plus has extremely high precision and mounting accuracy (±1.5µm), has a wide range of functions, and is used in micro-optics, LED and MEMS assembly, semiconductor advanced packaging (3D, Stack Die, etc.);
3. The accuracy of COS placement machine is ±1.5µm, which is suitable for silicon photonics, optical device packaging, data communication/5G, 3D sensor/lidar and augmented reality; the accuracy of NANO is ±2.0µm, which is suitable for silicon photonics and optical device packaging. Known as the placement system with the highest precision among similar products.
The company also has Fan-out WLP die-bonding equipment, which is the NUCLEUS series of full-efficiency high-precision pick-and-place; hot-pressing die-bonding equipment, is the FIREBIRD TCB series, etc.
Conclusion
With the popularization of advanced packaging technologies such as SiP system-in-package and 3D packaging, the proportion of packaging and testing equipment in the semiconductor equipment industry has gradually increased.
Advanced packaging production lines have also put forward higher requirements for the performance of die bond machines, including SMT The requirements for the accuracy, speed, yield rate, stable force control, temperature field and deformation control of the mounter will become higher and higher.
Die bonding process is an important process for semiconductor chip manufacturing.
The main steps of the die bonding process include: chip positioning, glue coating, chip alignment, heat curing, carrier separation and cleaning, etc.
Die bonder machine is divided into FC package placement machine, FO package placement machine and 2.5D/3D placement machine.
According to the application type: it can be divided into IC die bonder, discrete device die bonder, LED die bonder (SMT die bonder and COB die bonder), mainly used in semiconductor electric chips, optical chips, optical modules, silicon photonics Devices, sensors and other packaging processes.
